There are situations where doors need to be pried open during rescue operations, such as when a door of an automobile cannot be normally opened due to deformation of the automotive body caused by a traffic accident, or a door of a building cannot be normally opened due to the deformation of the building caused by an earthquake or a fire. Usually, a portable, hydraulic cutting and expanding tool generally called Combi Tools are used to open such a stuck door.
The applicant of the present patent application developed a portable, hydraulic tool capable of being easily operated by an operator and made a patent application for an invention related to the portable, hydraulic tool in Jpn. Pat. App. No. 2000-273697 and JP 2002-78988 A. This previously proposed portable, hydraulic tool includes a hydraulic power generating mechanism for generating hydraulic power, an electric motor for driving the hydraulic power generating mechanism, and a cylinder actuator provided with a piston and a piston rod. Working fluid pressurized by the hydraulic power generating mechanism drives the cylinder actuator to operate a working tool for opening and closing operations by the piston rod to cut and pry open a door or the like.
The hydraulic tool has a hydraulic circuit including a fluid passage through which the working fluid is supplied to the cylinder actuator and the working fluid is returned to a working fluid tank. A spool valve is placed in the fluid passage to control the operation of the working tool. The spool valve is operated manually to change the moving direction of the piston rod. The invention related to the patent application operates the spool valve by operating a slide handle disposed near the grip of the electric motor.
Since the slide handle for operating the spool valve of the hydraulic tool is disposed near the grip, the operator of the hydraulic operating device is able to control the hydraulic tool by operating the slide handle by hand-gripping the grip.
However, when the hydraulic tool is large or when the hydraulic tool needs to be pressed against a door or the like during a prying operation, the hydraulic tool cannot be stably held by the single hand and it is difficult to press the tip of the working tool firmly against the door or the like.
Since a finger of the hand gripping the grip is placed on the slide handle, it is difficult to hold the hydraulic operating device firmly.
Since the slide handle needs to be operated to operate the spool valve, the grip cannot be turned relative to a main casing, the positional relation between the grip and the main casing is fixed, and hence the operability of the hydraulic tool is unsatisfactory.
The present invention has been made in view of those problems and it is therefore an object of the present invention to provide a hydraulic tool capable of being stably held and of efficiently achieving opening and closing operations and working with reliability even under a condition where the hydraulic tool needs to exert a strong force on an object.